In order to maximize efficiency of a limited radio resource in a wideband wireless communication system, methods for more effectively transmitting data in time, space, and frequency domains have been provided.
Transmission of a control signal on the time, space, and frequency domains is an essential and indispensable factor to implement various transmission or reception methods for high-speed packet transmission. A channel for transmitting the control signal is referred to as a control channel. Examples of an uplink control signal include an acknowledgement (ACK)/negative-acknowledgement (NACK) signal that is a response for downlink data transmission, a channel quality indicator (CQI) indicating downlink channel quality, a sounding reference signal for uplink scheduling, a scheduling request signal for requesting uplink radio resource allocation, etc.
In general, there is a limitation in radio resources allocated to the control channel. This is because a transfer rate can be reduced when a large amount of radio resources are allocated to the control channel since a small amount of radio resources are allocated to a data channel (or traffic channel). However, scheduling may not be properly performed when the control signal is not transmitted. In particular, the uplink control signal is restrictively transmitted due to a limitation in power or battery capacity of a user equipment.
Accordingly, there is a need for a method capable of effectively transmitting various uplink control signals.